1. Field of the Invention
The present invention relates generally to medical imaging and, in particular, to a method and apparatus for combining a radiography system and a fluoroscopy system into a combined medical diagnostic system.
2. Description of the Related Art
Various types of image processing computers (for imaging systems) are used for the two clinical applications of medical diagnostics in fluoroscopy and radiography.
The two imaging systems are characterized by different properties with respect to the frequency and resolution of the generated medical images. In radiography images of unmoving subjects are generated with an optimally high resolution, while in fluoroscopy, images of moving subjects are predominantly generated that have a lower resolution than the images in radiography. In other words, radiography produces high resolution still images whereas fluoroscopy produces lower resolution moving images.
The known prior art provides that different systems are used for the image processing in the different systems for fluoroscopy and radiography. The computers which are used are optimized for the respective requirement of the imaging system. The most important characteristic data for the image computers of the various systems are listed in the following
For a Radiography System:
Image size: approximately 30002 (approximately 5-10 megapixels per image)
Image frequency: approximately 2 images per minute (with a maximum of 10 images per minute)
Duration of the image calculation: a maximum of a few seconds
Acceleration voltage of the x-ray tube: approximately 40-150 kV
Dose: 1 μGy to 10 μGy
Image processing algorithms: linear and non-linear, multiscalar frequency filters
Fluoroscopy:
Image size: approximately 10002 (approximately 1 megapixel per image)
Image frequency: approximately 0.5 images per second up to a maximum of 30 images per second
Duration of the image calculation: a few milliseconds
Acceleration voltage of the x-ray tube: approximately 40-90 kV
Dose: 3 nGy up to 1 μGy
Image processing algorithms: linear frequency filters
In addition to the technical data being handled by the two systems, the two different computers also exhibit differences in the operation since the workflows in the image generation are different between fluoroscopy and radiography. The different operating workflows between the two acquisition methods are thereby depicted in different operating interfaces on the computer monitors.
In systems with different detectors for fluoroscopy and radiography, an image chain must be provided for each different detector that can calculate images with the different resolution and frequency. These images are generated either by different radiation receivers for the different applications or may be generated by a combined radiation receiver for both image types.